package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.hmdp.dto.Result;
import com.hmdp.entity.SeckillVoucher;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisWorker;
import com.hmdp.utils.UserHolder;
import com.hmdp.utils.impl.SimpleRedisLock;
import io.netty.util.concurrent.SingleThreadEventExecutor;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.beans.BeanUtils;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.connection.stream.*;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.Duration;
import java.time.LocalDateTime;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.*;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private ISeckillVoucherService seckillVoucherService;

    @Resource
    private RedisWorker redisWorker;

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Resource
    private RedissonClient redissonClient;

    private static final DefaultRedisScript<Long> SECKILL_SCRIPT;

    static {
        SECKILL_SCRIPT = new DefaultRedisScript<>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }

    private static final ExecutorService SECKILL_EXECUTOR_SERVICE = Executors.newSingleThreadExecutor();

    private IVoucherOrderService proxy;

//    private BlockingQueue<VoucherOrder> order_task = new ArrayBlockingQueue<>(1024*1024);
//
//
    //类初始化后就执行此任务
//    @PostConstruct
//    private void init(){
//        SECKILL_EXECUTOR_SERVICE.submit(new VoucherOrderTask());
//
//    }

    private class VoucherOrderTask implements Runnable{

        String queueName = "stream.orders";
        @Override
        public void run() {

            while (true){
                //获取队列中订单信息
                try {
                   //获取消息队列中的订单信息 xreadgroup group g1 c1 count 1 block 2000 streams streams.order
                    List<MapRecord<String,Object,Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1","c1"),
                            StreamReadOptions.empty().count(1).block(Duration.ofSeconds(2)),
                            StreamOffset.create(queueName, ReadOffset.lastConsumed())
                    );
                    //判断消息获取是否成功
                    if (list == null || list.isEmpty()){
                        continue;
                    }

                    //解析消息中的订单信息
                    MapRecord<String,Object,Object> record = list.get(0);
                    Map<Object,Object> values = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values,new VoucherOrder(),true);

                    //如果获取成功,进行下单
                    handleVoucherOrder(voucherOrder);

                    //ACK确认
                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());
                } catch (Exception e) {
                    log.error("订单处异常场",e);
                    handlePendingList();
                }
            }
        }
    }

    private void handlePendingList() {
        String queueName = "stream.orders";

        while (true) {
            {
                //获取队列中订单信息
                try {
                    //获取pending-list中的订单信息 xreadgroup group g1 c1 count 1 block 2000 streams streams.order
                    List<MapRecord<String,Object,Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1","c1"),
                            StreamReadOptions.empty().count(1),
                            StreamOffset.create(queueName, ReadOffset.from("0"))
                    );
                    //判断消息获取是否成功
                    if (list == null || list.isEmpty()){
                        //没有异常消息，结束循环
                        break;
                    }

                    //解析消息中的订单信息
                    MapRecord<String,Object,Object> record = list.get(0);
                    Map<Object,Object> values = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(values,new VoucherOrder(),true);

                    //如果获取成功,进行下单
                    handleVoucherOrder(voucherOrder);

                    //ACK确认
                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());
                } catch (Exception e) {
                    log.error("处理pending-list异常",e);
                    try {
                        Thread.sleep(20);
                    } catch (InterruptedException ex) {
                        throw new RuntimeException(ex);
                    }
                }
            }
        }
    }

    private void handleVoucherOrder(VoucherOrder voucherOrder) {

        //获取用户
        Long userId = voucherOrder.getUserId();

        RLock lock = redissonClient.getLock("lock:order:" + userId);
       //获取锁
        boolean isLock = lock.tryLock();
        //判断获取锁是否成功
        if (!isLock){
            log.error("不允许重复下单");
            return;
        }

        try {
             proxy.createVoucherOrder(voucherOrder);
        } catch (IllegalStateException e) {
            throw new RuntimeException(e);
        } finally {
            //释放锁
            lock.unlock();
        }
    }

    @Override
    public Result seckillVoucher(Long voucherId) {

        //获取用户
        Long userId = UserHolder.getUser().getId();
        //获取订单id
        long orderId = redisWorker.nextId("order");
        //执行lua脚本
        Long result = stringRedisTemplate.execute(
                SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(),userId.toString(),String.valueOf(orderId)
        );

        //判断结果是否为0
        int r = result .intValue();
        if (r!=0){
            //不为0，没有购买资格
            return Result.fail(r ==1 ? "库存不足" : "不能重复下单");
        }

        //获取代理对象
        //获取代理对象（事务）
        IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();

        return Result.ok(orderId);
    }

//    @Override
//    public Result seckillVoucher(Long voucherId) {
//
//        //获取用户
//        Long userId = UserHolder.getUser().getId();
//
//        //执行lua脚本
//        Long result = stringRedisTemplate.execute(
//                SECKILL_SCRIPT,
//                Collections.emptyList(),
//                voucherId.toString(),userId.toString()
//        );
//
//        //判断结果是否为0
//        int r = result .intValue();
//        if (r!=0){
//            //不为0，没有购买资格
//            return Result.fail(r ==1 ? "库存不足" : "不能重复下单");
//        }
//
//        //为0，有购买资格，把下单信息保存到阻塞队列
//        VoucherOrder voucherOrder = new VoucherOrder();
//        //订单id
//        long orderId = redisWorker.nextId("order");
//        voucherOrder.setId(orderId);
//        voucherOrder.setUserId(userId);
//        voucherOrder.setVoucherId(voucherId);
//        order_task.add(voucherOrder);
//
//        //获取代理对象
//        //获取代理对象（事务）
//        IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
//
//        return Result.ok(orderId);
//    }

//    @Override
//    @Transactional
//    public Result createVoucherOrder(Long voucherId) {
////        //一人一单
////        Long userId = UserHolder.getUser().getId();
////
////        //查询订单
////        int count = query().eq("user_id", userId).eq("voucher_id", voucherId).count();
////        //判断是否存在
////        if (count > 0) {
////            return Result.fail("用户已经购买过一次");
////        }
////
////        //扣减库存
////        boolean success = seckillVoucherService.update()
////                .setSql("stock = stock -1"). //set stock = stock-1
////                        eq("voucher_id", voucherId)
////                .gt("stock", 0).update(); //stock > 0
////
////        if (!success) {
////            //扣减失败
////            return Result.fail("库存不足！");
////        }
////
////        //创建订单
////        VoucherOrder voucherOrder = new VoucherOrder();
////
////        //订单id
////        long orderId = redisWorker.nextId("order");
////        voucherOrder.setId(orderId);
////        voucherOrder.setUserId(userId);
////        //代金券Id
////        voucherOrder.setVoucherId(voucherId);
////        save(voucherOrder);
//
////        return Result.ok(orderId);
////    }
//
    @Override
    public void createVoucherOrder(VoucherOrder voucherOrder) {
        //一人一单
        Long userId = voucherOrder.getUserId();

        //查询订单
        int count = query().eq("user_id", userId).eq("voucher_id", voucherOrder.getVoucherId()).count();
        //判断是否存在
        if (count > 0) {
            log.error("用户已经购买过一次");
            return;
        }

        //扣减库存
        boolean success = seckillVoucherService.update()
                .setSql("stock = stock -1"). //set stock = stock-1
                        eq("voucher_id", voucherOrder)
                .gt("stock", 0).update(); //stock > 0

        if (!success) {
            //扣减失败
            log.error("库存不足");
            return;
        }
        save(voucherOrder);
    }
//
////    @Override
////    @
////    public Result seckillVoucher(Long voucherId) {
////
////        //查查询优惠券
////        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
////        //判断秒杀是否开始
////        if (voucher.getBeginTime().isAfter(LocalDateTime.now())){
////            return Result.fail("描述尚未开始");
////        }
////
////        //判断是否结束
////        if (voucher.getEndTime().isBefore(LocalDateTime.now())){
////            return Result.fail("秒杀已经结束");
////        }
////
////
////        //判断库存是否充足
////        if (voucher.getStock()<1) {
////            return Result.fail("库存不足");
////        }
////        //一人一单
////        Long userId = UserHolder.getUser().getId();
////
////        //先获取锁提交事务再释放锁
////       // synchronized (userId.toString().intern()) {
////
////            //使用分布式锁
////        //创建锁对象
////    //    SimpleRedisLock lock = new SimpleRedisLock(stringRedisTemplate,"order:"+userId);
////       //使用redisson的锁
////        RLock lock = redissonClient.getLock("lock:order:" + userId);
////       //获取锁
////        boolean isLock = lock.tryLock();
////        //判断获取锁是否成功
////        if (!isLock){
////            return Result.fail("不允许重复下单");
////        }
////
////        try {
////            //获取代理对象（事务）
////            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
////            return proxy.createVoucherOrder(voucherId);
////        } catch (IllegalStateException e) {
////            throw new RuntimeException(e);
////        } finally {
////            //释放锁
////            lock.unlock();
////        }
//
//
//        // }
//
//
}
